Liquid flow indicator



y 3, 1955 A. WlTTLlN 2,744,488

' LIQUID FLOW INDICATOR Filed 00:. 11. 1952 IN VEN TOR.

Q/Mz Mil/02 United States PatentO This invention relates to an indicator adaptedtto :be interposed in a circulatory system whereby to ;reveal not "on'lyithe presence of a fluidpassingtherethroughibut also,

in 'rnany cases, its conditi'on-aswe1l. :M'oreparticularly the present features of improvementsare concerned with a protecting sleeve which surrounds the-indicator iandtis movable axially from one position to another-whereby toa'fiord a :view of 'the indicator window and of the fluid exposed 'therethrough, orto fully cover the-window'and establish a sealing connection with 'the'housing therefor. Such a'protecting sleeve is eifective to prevent any loss of 7 fluid in the event-that "the window should be broken: or that its mounting within the housing should not :remain fluid-tight.

This application 'is a continuation in-part of: my: copen-ding-application, Serial No. 194;:144, filed November 4, 1950.

".The "present indicator'has been designed with special reference to arefrigerator systems wherein aare'frigerant -is required to'he circulated through aline under :pressnres which may at times 'reachi250 lbs; suchraniindicatorais provided with an enlarged -elongated housing WhCIBlIlviS mounted 'a :transparent cylinder :through which": the Lfillid freely moves Without deviating fromcstraightline. ":The cylinder mounting is such as -to -p'errnit the .-'cylinder 1to float in a wholly unstressed condition, while exposingia considerable :portion of its surface to'zview so =thatrithe presence or condition 'of "the fiui'd therewit in :may :be

ascertained'readily 'by'inspection. I

The "protector sleeve for the transparent; cylinder is normally advanced 'into sealing engagement'zwith a pair of spaced gaskets -at opposite fends Of the'Wind0W, ithe arrangement' being:such-that if the windowwshould leak or break, the fluid escaping therethroughzwill beconfinerlrby thesleeve betweenthe twosealing: gaskets. 3Such==a sleeve, however, maybe readily shifted 'axiall-yithe short distance that is required to-"fully exposethe windowvwhereby to permit an inspection of the flu-id passing"1'therewithin. v

The' sealing gaskets-with wliichfthe sleeve: cooperatesimay optionallybe carried'by a'pair of-rings which aref threaded :connection with the 'exteriorof the' housing,

these rings-serving additionally as couplings for errdffittings i which are comprised in the indicator housing.

Certain embodimentsf this. invention are set forth systemiincorporating theusual :operating funitsvzan'd also theindicatoro'fthis invention;

Figure 2 is a longitudinal sectionalwview :throug'h': the indicator showing the ziprotecting sleeve in the inormal position where :it is inrsealingtengagementawith thezgaskets therefor;

Figure 3, which is :a, :similar view; showsdhe ssealing ringshifte'd axiallyrtoza second:position'where;thethousing window isexposedtoviemiand 1 r I Figure :43. iszra;fragrnentary. sectional;;elevationrthrough a sealingrring:orsshield;illustratingzsa;secondcembodiment of'theinvention. i

ln' the showing r of Figure 1, there is a compressor-A from which a refrigerant is pumped under pressure 'throug'h-a'lineof tubingS to a condenser B. A'tubing line 6 'extends from'the condenserthrough to an-evapo- -ratorC an'd-fromthenceanother line of-tubing 7"leads back to" the -.compressor. A fluid'flow regulator-8-is :desirably included 'in a the system. The indicator of the present invention, designated as 9, e is 'also interposed; in this system at any convenient point. i

The "present indicator comprises three principal parts, -viz. an elongated tubular housing H andat each "end thereof a head or-coupling member lfl having anaxially'extended nipple "11' which is threaded-exteriorly to receive a coupling 12 whereby to establish connectionwith-the circulatory line of arefrigerating system or "the "like. Window openings 14 are provided on opposite sides'of thei housing as shown.

In the construction shown, 'each nipple head is formed 'on its 'end proximate to the housing with *an annular "groove 1i5-wherein is fitted -'a resilient gasket 16 which engages one end-of-a transparentcylinder 1 8 of'glasscr the lik e serving as a sight tube that isvisible 1 through 'either window l l. "There is-alsointer-posed 'a-gasket '20 between eachhead 10 and thehousing H-to establish a 'fiuid tight connection therebetween.

'The two -heads 'may be joinedto the housing bymeans ofrings 25 and 26-each of which is in screw threaded connection with one end portion thereof; each ring "also extends axially beyond the proximate housing end to receive engagement'from' the threaded end-portion of the head. Aftereach-ring'has been screwed in-place on'the housing'or on'-its=associated*hea'd, the part-to be coupled thereto is also fitte'd into the ring andadvanced rotatively therewithin. The threaded-portions of the housing are desirably --exten'ded to a predetermined pointzendwise thereof-so that each'ring-ZS-and 26,-Whenadvanced to'its limit thereon, will 'be spaced a-predetermined distance from the other. This is important for avreason which will presently appear.

In the embodiment of the invention illustrated in the accompanyingdrawings, the 5 locking means forrlinterlocking the.coupling members .10 and sight tube .18;i n fluid-tight relationshipflincludes .the gaskets .16 at-ythe ends of'thesighttube, the hQusingQH-Which extends between andhasits outer surface aligned with the coupling memb,ers,10, and the twoendrings125 and"26 which joinithe couplingmembers or head 10 tothe ends :of-thehousing .I,-l,.,as illustrated mostclearly in Figure 2. 'lhe-effectiof this combination, therefore, is: that the; coupling members .10: may beadvanced toward each otherby-turning oneor .bQth; coupling tmemb'ers relative 4 to :one cr both-rings '25 and,26. Thiscserves to compress the .-ga'sketsil'5 against the ends ofrthegsight tube;18- and against'theradjacent ends of the/coupling membersi10 to make a-"fluid-tight seal betweenthe coupling-members 'ltlrand sight tube 18 in -';the manner illustrated. :Furthermore,iif thereshould be some :yielding of the gaskets r 16, thismay be'easily taken upiby merely vturningone or both of the coupling members inthe manner just described.

\The outside diameter oflthe:ring:26 is 'somewhat' larger thaniszthat ,of-"the ring 25. "It is also contoured'with a :circular base28 fromwhich upstands a shoulder 29 which Tfaces:laterallytowardcthe smaller ring'25 whereon 'is also formedy-a circularbase '31 of lesser diameter having a ,sh0ulder32 at one endthereof. The shoulders of the two rings-face'iimthesame direction and are of unequal diameters-correspondinggenerally tothe differential inthe diameters of'theirrespective bases. The circular baseZS -of-thelargerring'26 is formed with projecting threadsf 35 which-terminate short of :theshoulder29 to-provide:a seat'for a'sealing gasket 3.6. A seat is also provided ea'dja cent the shoulder 32 for reception of a second sealing gasket 38.

The protecting ring or fluid impervious shield S which is a feature of this invention is formed with an outside diameter substantially the same as that of the larger shoulder 29 and with an internal diameter substantially the same as that of its circular base 28. Screw threads 39 are formed internally of the sleeve at one end, and 2 when assembled in place the sleeve is adapted to engage the larger ring 26 and establish a screw threaded connec tion therewith. The opposite end of the sleeve S is formed with a flange 40 which extends inwardly a distance about equal to the height of the smaller shoulder 32 so as to substantially engage its circular base 31. The larger end of the sleeve is shown as beveled slightly, at 41, and a similar bevel 42 is provided inwardly of the flange 40, these two beveled faces being arranged to engage the gaskets 36 and 38, respectively, and compress them slightly inwardly.

When the sleeve is assembled in place, it is moved past the small ring so as to engage with the threads 35 on the circular base 28 of the larger ring. By rotating the sleeve to its limit, the gasket 36 is engaged concurrently with engagement of the gasket 38, and both are placed under substantially equal pressures when the axial movement of the sleeve is arrested. The sleeve, when so positioned, provides an annular wall spaced outwardly from the housing H and in sealing engagement with the two rings 25 and 26 so that any fluid escaping through the housing window will be confined to the space inwardly of the sleeve.

When an inspection is to be made, the sleeve is rotated to move axially away from the circular base 28 and when I disengaged therefrom is free to be shifted endwise to fully expose the transparent window. The sleeve may then be left in this disconnected position, or be replaced in sealing position over the housing window. Thus there will always be ample protection, either maintained or available, to prevent any loss of fluid from the housing should there be any loss of fluid through or around the glass viewing cylinder.

An alternate embodiment of the invention is illustrated in Figure 4. In this embodiment the sealing ring or shield S has an opening in one portion of its wall provided with a pressure responsive signal device operable by pressure within the shield to notify an observer of a leak in the fluid flow indicator. This pressure responsive signal device,

-as illustrated in the drawings, includes an outwardly projecting tubular member 50 positioned in an opening in the shield and provided on its outer end with an inwardly projecting annular flange 58. As can be seen in Figure 4, the tubular member 50 extends beyond the outer surface of the shield. Positioned within the tubular member 50 is a movable pressure responsive signal member 51 that is movable outwardly under the influence of internal pressure within the shield S. This signal member 51, therefore, acts as a piston movably mounted within the member 50. The signal member 51 is preferably provided with an attention attracting indicia member such as the raised projection 52 so that when the signal member 51 has been moved outwardly by internal pressure, the raised projection 52 will be moved into position to be viewed by an observer. When this occurs, the signal member 51 seats against an annular gasket 53 on the inner surface of the flange 58 and makes sealing engagement therewith to prevent escape of fluid around the sides of the member 51. The internal pressure within the shield will hold the signal member 51 against this gasket. Thus there will be no leakage of fluid and a maintenance man can interrupt the fluid flow to replace or repair the portion of the indicator that has failed. This alternate embodiment illustrated in Figure 4 immediately indicates when there is a leak in the indicator and when the fluid flow must be interrupted before the shield S is removed.

As is evident from the above description, any type of pressure responsive signal device may be used as desired. This device has the important feature of notifying an observer, such as a maintenance man, that either the transparent tube 18 has been accidentally broken, that there has been a failure in a gasket or that some similar accident has occurred to permit the fluid to escape from the indicator and bear against the signal device. When such a signal device is not provided, there is always danger that an internal break has occurred and the operator is not aware of this until he begins to remove the shield. This, of course, cannot occur in the embodiment illustrated in Figure 4 of the drawings.

Having described my invention as related to the embodirnents shown in the drawings, it is my intention that the invention be not limited by any of the details of description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the accompanying claims.

I claim:

1. A fluid flow indicator, comprising: a pair of spaced coupling members attachable in fluid flow relationship to a fluid line; a transparent sight tube extending between the coupling members through which the fluid is adapted to flow; locking means for interlocking the coupling members and sight tube in fluid tight relationship; a readily removable fluid impervious shield normally surrounding the sight tube but removable to expose the sight tube; and means sealing the shield to the assembly in fluid tight relationship when the shield is in position surrounding the sight tube. I

2. A fluid flow indicator, comprising: a pair of spaced coupling members attachable in fluid flow relationship to a fluid line; a transparent sight tube extending between the coupling members through which the fluid is adapted to flow; locking means for interlocking the coupling members and sight tube in fluid tight relationship, the locking means being provided with annular sealing portions adjacent to the opposite ends of the sight tube; and a readily removable tubular fluid impervious shield normally arranged in fluid tight relationship against said portions and surrounding the tube but movable longitudinally of the indicator and away from said portions to expose the sight tube.

3. The indicator of claim 2 wherein said portions comprise annular shoulders with the first shoulder having an outside diameter not greater than the inside diameter of the end of the shield engageable with the second shoulder to permit slipping the shield over the first shoulder and into sealing engagement with both shoulders.

4. The indicator of claim 3 wherein each shoulder is provided with a sealing gasket, the end portions of the shield bearing against the gaskets when the shield is in its normal position around the sight tube.

5. A fluid flow indicator, comprising: a pair of spaced coupling members attachable in fluid flow relationship to a fluid line; a transparent sight tube extending between the coupling members through which the fluid is adapted to flow; locking means for interlocking the coupling members and sight tube in fluid tight relationship; a readily removable fluid impervious shield normally surrounding the sight tube but removable to expose the sight tube; means sealing the shield to the assembly in fluid tight relationship when the shield is in position surrounding the sight tube; and a pressure responsive signal member operable by pressure within the shield thereby to notify an observer of a leak in the indicator.

6. The flow indicator of claim 5 wherein the signal member is mounted on the shield and communicates with the interior thereof.

7. A fluid flow indicator, comprising: a pair of spaced coupling members attachable in fluid flow relationship to a fluid line; a transparent sight tube extending between the coupling members through which the fluid is adapted to flow; locking means for interlocking the coupling members and sight tube in fluid tight relationship; a readily removable fluid impervious shield normally surrounding the sight tube but removable to expose the sight tube; means sealing the shield to the assembly in fluid tight relationship when the shield is in position surrounding the sight tube; an outwardly projecting tubular member communicating with the interior of the shield; and a movable pressure responsive signal member in the tubular member movable outwardly under internal pressure thereby to notify an observer of a leak in the indicator.

8. The flow indicator of claim 7 wherein the signal member carries an attention attracting indicia visible externally when the signal member is moved into signalling position.

References Cited in the file of this patent UNITED STATES PATENTS Waters Sept. 8, 1903 Deming May 28, 1935 Hoffman July 13, 1948 Wittlin June 10, 1952. Gray Jan. 5, 1954 

